1. Field of the Invention
The present invention relates to vacuum adsorbers which are able to adsorb objects with uneven surfaces without slipping.
2. Description of the Related Art
Conventional vacuum adsorbers include an adsorption member made from an elastic material, such as rubber, so as to have a vacuum cavity in which a vacuum is generated to thereby adsorb an object.
However, there are many cases of slipping between the conventional vacuum adsorber and the object adsorbed. If the object to be adsorbed has a very low friction resistance, such as glass, it falls by gravity when the vacuum adsorber is tilted to a large angle. Even where the object has a relatively large friction resistance, if it is wet, the same problem occurs.
Where the object has a dent, there is a gap between the vacuum adsorber and the object drawing air therethrough so that the adsorber fails to adsorb the object. If the vacuum is made very large in order to increase the adsorption power, the elastic adsorption member can be sucked into the vacuum cavity, failing to work.